Experimental Evaluation of Sorbents for Sulfur Control in a Coal-Fueled Gas Turbine Slagging Combustor

1990 ◽  
Author(s):  
L. H. Cowell ◽  
C. S. Wen ◽  
R. T. LeCren
Keyword(s):  
Sulfur Dioxide ◽  
Gas Turbine ◽  
Hydrated Lime ◽  
Capture Efficiency ◽  
Water Mixture ◽  
Dolomitic Lime ◽  
Bench Scale ◽  
Primary Zone ◽  
Secondary Zone ◽  
Sulfur Capture

A slagging combustor has been used to evaluate three calcium-based sorbents for sulfur capture efficiency in order to assess their applicability for use in a coal-fueled gas turbine. Testing is completed in a bench-scale combustor with one-tenth the heat input needed for the full-scale gas turbine. The bench-scale rig is a two-staged combustor featuring a fuel rich primary zone and a fuel lean secondary zone. The combustor is operated at 6.5 bars with inlet air preheated to 600 K. Gas temperatures of 1840 K are generated in the primary zone and 1280 K in the secondary zone. Sorbents are fed in either the secondary zone or mixed with the coal water mixture and fed into the primary zone. Dry powdered sorbents are fed into the secondary zone by an auger into one of six secondary air inlet ports. The three sorbents tested in the secondary zone include dolomite, pressure hydrated dolomitic lime, and hydrated lime. Sorbents have been tested while burning coal water mixtures with coal sulfur loadings of 0.56 to 3.13 weight percent sulfur. Sorbents are injected into the secondary zone at varying flow rates such that the calcium/sulfur ratio varies from 0.5 to 10.0. Hydrated lime exhibits the highest sulfur dioxide reductions in the exhaust of 90%. Pressure hydrated dolomitic lime and dolomite reduce SO2 concentrations by 82% and 55%, respectively. Coal sulfur loading is found to have a small influence on sorbent sulfur capture efficiency. Pressure hydrated dolomitic lime ground with the coal during coal water mixture preparation and injected into the primary zone is found to lower the sulfur dioxide concentration by an insignificant amount.

Experimental Evaluation of Sorbents for Sulfur Control in a Coal-Fueled Gas Turbine Slagging Combustor

1992 ◽  
Vol 114 (1) ◽  
pp. 152-158 ◽  
Author(s):  
L. H. Cowell ◽  
C. S. Wen ◽  
R. T. LeCren
Keyword(s):  
Sulfur Dioxide ◽  
Gas Turbine ◽  
Hydrated Lime ◽  
Capture Efficiency ◽  
Water Mixture ◽  
Dolomitic Lime ◽  
Bench Scale ◽  
Primary Zone ◽  
Secondary Zone ◽  
Sulfur Capture

A slagging combustor has been used to evaluate three calcium-based sorbents for sulfur capture efficiency in order to assess their applicability for use in a coal-fueled gas turbine. Testing is completed in a bench-scale combustor with one-tenth the heat input needed for the full-scale gas turbine. The bench-scale rig is a two-stage combustor featuring a fuel-rich primary zone and a fuel-lean secondary zone. The combustor is operated at 6.5 bars with inlet air preheated to 600 K. Gas temperatures of 1840 K are generated in the primary zone and 1280 K in the secondary zone. Sorbents are either fed into the secondary zone or mixed with the coal-water mixture and fed into the primary zone. Dry powdered sorbents are fed into the secondary zone by an auger into one of six secondary air inlet ports. The three sorbents tested in the secondary zone include dolomite, pressure-hydrated dolomitic lime, and hydrated lime. Sorbents have been tested while burning coal-water mixtures with coal sulfur loadings of 0.56 to 3.13 weight percent sulfur. Sorbents are injected into the secondary zone at varying flow rates such that the calcium/sulfur ratio varies from 0.5 to 10.0. Hydrated lime exhibits the highest sulfur dioxide reductions in the exhaust of 90 percent. Pressure-hydrated dolomitic lime and dolomite reduce SO2 concentrations by 82 and 55 percent, respectively. Coal sulfur loading is found to have a small influence on sorbent sulfur capture efficiency. Pressure-hydrated dolomitic lime ground with the coal during coal-water mixture preparation and injected into the primary zone is found to lower the sulfur dioxide concentration by an insignificant amount.

The Influence of Coal Slurry Fuel Properties on the Performance of a Bench Scale Two-Stage Slagging Combustor

1992 ◽  
Author(s):  
L. H. Cowell ◽  
C. S. Wen ◽  
R. T. LeCren
Keyword(s):  
Pollutant Emissions ◽  
Test Facility ◽  
Inlet Temperature ◽  
Coal Slurry ◽  
Particulate Emissions ◽  
Two Stage ◽  
Bench Scale ◽  
Air Inlet ◽  
Primary Zone ◽  
Secondary Zone

Fuel specifications for a coal-fueled industrial gas turbine are being determined through bench scale testing of a two-stage slagging combustor with coal water mixtures (CWM) possessing different properties. Twelve CWMs have been formulated with variations in coal loading, ash concentration, fuel additives, coal particle size, and coal type. The test combustor is operated at 7 bars with a 600 K air inlet temperature in a high pressure test facility. The two-stage slagging combustor (TSSC) features a rich burning, slagging primary zone and a lean secondary zone. Combustor performance is characterized by measurements of pollutant emissions, slag capture, particulate emissions, and coal utilization. The combustor has demonstrated a high degree of fuel property flexibility with performance remaining above goals in most tests. The properties of the CWMs and the test results are discussed.

scholarly journals Development of a Coal-Fueled Gas Turbine Slagging Combustor

1989 ◽  
Author(s):  
L. H. Cowell ◽  
R. T. LeCren
Keyword(s):  
Gas Turbine ◽  
Computer Modelling ◽  
Combustion Process ◽  
Development Program ◽  
Water Mixture ◽  
Fuel Injector ◽  
Cross Sectional ◽  
Fuel Injectors ◽  
Primary Zone ◽  
Multiple Jets

A slagging combustor for a coal-fueled gas turbine engine is being developed. The work to date has been accomplished using a bench-scale combustor with one-tenth the heat input required for the full-scale gas turbine unit. The combustor features a fuel-rich slagging primary zone with hot refractory walls. Both single and multiple primary air/fuel injectors have been tested. Aerodynamic jet impaction on a target at one end of the primary zone removes much of the slag. The jet impaction is the result of the single air/fuel injector flow for multiple injectors, the intersection of the multiple jets forms a central jet. There is an additional particulate rejection impact separator between the primary and secondary zones to remove the slag that escapes the primary zone. Secondary air is introduced via multiple jets that rapidly mix with the incoming gas from the particulate removal device, resulting in a minimal formation of thermal NOx and the completion of the combustion process. Variables that have been evaluated include coal-water mixture properties such as top and mean particle size, viscosity, loading and ash fusion temperature, and primary zone parameters such as volume, cross-sectional area, loading, and equivalence ratio. Combustor performance was compared with single or multiple fuel injectors, relating the combustor performance to the spray characteristics of the two injector configurations. Modifications of the single injector were evaluated with the goal of attaining at least the same atomization performance as the smaller injectors used in the multiple injector configuration. Flow visualization, computer modelling, and cold-flow velocity traverses have been employed to aid the development program. The results of the subscale development are being used to design and develop the full-size combustor for integration with the engine.

Bench Scale Testing of Low-NOx LBG Combustors

1982 ◽  
Vol 104 (1) ◽  
pp. 120-128 ◽  
Author(s):  
W. D. Clark ◽  
B. A. Folsom ◽  
W. R. Seeker ◽  
C. W. Courtney
Keyword(s):  
Gas Turbine ◽  
Residence Time ◽  
Attractive Alternative ◽  
Nox Emissions ◽  
Catalytic Reactor ◽  
Power Cycle ◽  
Bench Scale ◽  
Gasification Process ◽  
Stirred Reactor ◽  
Catalytic Reformer

The high efficiencies obtained in a combined gas-turbine/steam-turbine power cycle burning low Btu gas (LBG) make it a potentially attractive alternative to the high sulfur emitting direct coal-fired steam cycle. In the gasification process, much of the bound nitrogen in coal is converted to ammonia in the LBG. This ammonia is largely converted to nitrogen oxides (NOx) in conventional combustors. This paper examines the pressurized bench scale performance of reactors previously demonstrated to produce low NOx emissions in atmospheric laboratory scale experiments. LBG was synthesized in a catalytic reformer and fired in three reactors: a catalytic reactor, a diffusion flame, and a stirred reactor. Effects of scale, pressure, stoichiometry, residence time, and preheat were examined. Lowest NOx emissions were produced in a rich/lean series staged catalytic reactor.

scholarly journals The Development of a Diesel Burning Combustion Chamber With a Multiple Jet Primary Zone

1987 ◽  
Author(s):  
R. V. Cottington ◽  
J. P. D. Hakluytt ◽  
J. R. Tilston
Keyword(s):  
Gas Turbine ◽  
Shear Layers ◽  
Fuel Quality ◽  
Carbon Formation ◽  
Gas Turbine Combustor ◽  
Smoke Emission ◽  
Primary Zone ◽  
Efficient Combustion ◽  
Operational Range ◽  
Lean Conditions

A new primary zone for a gas turbine combustor has been developed which achieves efficient combustion in fuel lean conditions for minimizing carbon formation. This uses a large number of jets in the head of the chamber to generate independent shear layers in a co-operative array. Good combustion performance, wide fuel/air ratio operational range and tolerance to fuel quality have been demonstrated on research rigs. The combustor itself has been developed to an engine standard for a naval gas turbine required to operate with low smoke emission on distillate diesel fuel. The rig programme used to optimise the design is described together with results from engine evaluation. Practical advantages of this type of chamber apply equally to aero applications on kerosene.

Combustion of Coal/Water Mixtures With Thermal Preconditioning

1987 ◽  
Vol 109 (3) ◽  
pp. 313-318 ◽  
Author(s):  
M. Novack ◽  
G. Roffe ◽  
G. Miller
Keyword(s):  
Gas Turbine ◽  
Combustion Efficiency ◽  
Experimental Program ◽  
Water Mixture ◽  
Gas Turbine Combustor ◽  
Hydrocarbon Gases ◽  
Sampling Probe ◽  
Stable Flame ◽  
Thermal Preconditioning ◽  
Gaseous Form

Thermal preconditioning is a process in which coal/water mixtures are vaporized to produce coal/steam suspensions, and then superheated to allow the coal to devolatilize producing suspensions of char particles in hydrocarbon gases and steam. This final product of the process can be injected without atomization, and burned directly in a gas turbine combustor. This paper reports on the results of an experimental program in which thermally preconditioned coal/water mixture was successfully burned with a stable flame in a gas turbine combustor test rig. Tests were performed at a mixture flowrate of 300 lb/hr and combustor pressure of 8 atm. The coal/water mixture was thermally preconditioned and injected into the combustor over a temperature range from 350°F to 600°F, and combustion air was supplied at between 600°F to 725°F. Test durations varied between 10 and 20 min. Major results of the combustion testing were that: A stable flame was maintained over a wide equivalence ratio range, between φ = 2.2 (rich) and 0.2 (lean); and combustion efficiency of over 99 percent was achieved when the mixture was preconditioned to 600°F and the combustion air preheated to 725°F. Measurements of ash particulates, captured in the exhaust sampling probe located 20 in. from the injector face, show typical sizes collected to be about 1 μm, with agglomerates of these particulates to be not more than 8 μm. The original mean coal particle size for these tests, prior to preconditioning, was 25 μm. Results of additional tests showed that one third of the sulfur contained in the solids of a coal/water mixture with 3 percent sulfur was evolved in gaseous form (under mild thermolized conditions) mainly as H2S with the remainder as light mercaptans.

scholarly journals Testing of a Full Scale, Low Emissions, Ceramic Gas Turbine Combustor

1997 ◽  
Author(s):  
K. Smith ◽  
A. Fahme
Keyword(s):  
Gas Turbine ◽  
Engine Performance ◽  
Combustion Efficiency ◽  
Full Scale ◽  
Significant Deterioration ◽  
Lean Premixed Combustion ◽  
Fuel Injectors ◽  
Primary Zone ◽  
Test Engine ◽  
Cooling Air

The design and development testing of a full scale, low emissions, ceramic combustor for a 5500 HP industrial gas turbine are described. The combustor was developed under a joint program conducted by the U.S. DOE and Solar Turbines. The ceramic combustor is designed to replace the production Centaur 50S SoLoNOx burner which uses lean-premixed combustion to limit NOx and CO to 25 and 50 ppm, respectively. Both the ceramic and production combustors are annular in shape and employ twelve premixing, natural gas fuel injectors. The ceramic combustor design effort involved the integration of two CFCC cylinders (76.2 cm [30 in.] and 35.56 cm [14 in.] diameters) into the combustor primary zone. The ceramic combustor was evaluated at Solar in full scale test rigs and a test engine. Performance of the combustor was excellent with high combustion efficiency and extremely low NOx and CO emissions. The hot walls of the ceramic combustor played a significant role in reducing CO emissions. This suggests that liner cooling air injected through the metal production liner contributes to CO emissions by reaction quenching at the liner walls. It appears that ceramics can serve to improve combustion efficiency near the combustor lean limit which, in turn, would allow further reductions in NOx emissions. Approximately 50 hours of operation have been accumulated using the ceramic combustor. No significant deterioration in the CFCC liners has been observed. A 4000 hour field test of the combustion system is planned to begin in 1997 as a durability assessment.

Ash Behavior During Combustion and Deposition in Coal-Fueled Gas Turbines

1987 ◽  
Vol 109 (3) ◽  
pp. 325-330 ◽  
Author(s):  
C. L. Spiro ◽  
S. G. Kimura ◽  
C. C. Chen
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Alkali Metals ◽  
Coal Ash ◽  
Water Mixture ◽  
Corrosion Rates ◽  
Petroleum Fuels

Chemical and physical transformations of coal ash during combustion and deposition in gas turbine environments have been studied. Extensive characterization of the coal-water mixture fuel and deposits obtained on deposition pins and turbine nozzle vanes has been performed. The behavior of alkali metals has been found to be much different from that for petroleum fuels, resulting in lower than expected deposition and probable reduced corrosion rates.

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